Dbill head



Reissues Nev. 1o, 1925. Y

UNITED" STATES ALBED E. WILLIAMS, OF COPTER HILL, ARIZONA.

DRILL HEAD.

Original No. 1,498,598, dated `Tune 24, 1924, Serial No, v695,874, tiled February 28, 1924. 'Application for reissue led May 18, 1925. Serial No. 31,239.

To all whom 'it may concern;

Be it known 'that I, ALFRED E. VVILLAMS, a citizen of the United States, residing at Copper Hill, in the county of Gila and State of Arizona, vhave invented or discovered certain new and useful Improvements in Drill Heads, of which the following is a specification, reference being had therein to the accompanying drawing.

In the use' of that class of 4pneumatic drilling machines known as stope hammer machines the front heads, which are vusually of cast metal, and in which the drills work, become so badly worn, interiorly, after about thirty days use, that they have to be replaced by/new heads at considerable expense. The present invention has for its object to lessen this expense and thus ex- .tend the working life of the drill heads by providing the same with spring steel ushings which are inserted in such a mannerithat they are securely fixed in place, for the working operation; but which, when they'become somewhat Worn, may be removed and replaced by new bushings, all as will hereinafter more fully appear.

In the accompanying drawing Fig. 1 is a lon 'tudin'al section of a. stope hammer drill heal embodying the present invention, and Fig. 2 is a cross section of a slightly different form of the same on line 2 2, Fig. 1, showing a drill ofwell known construction in place in the head. i

vvReferringl to the drawing, 12 denotes a drill head of Well known form, the sameI v being provided with vears 13 having bolt holes 14 toenable it to be attached to the body of the machine. Within this drill head is--a bushing 15 made from spring steel workedout at a cherry red or low heat unvder a hammer, so that it becomes Yvery tough,

thus enabling it to wear well in use. The bushing 15 may be split longitudinally, as indicated by the 1ine'15, or may be integral as shown in Fig. 2. The central opening o-f the drill head which receives this bushing, or the bushing itself, is slightly tapered to the extent of about 1/8 or 33g of an ineh for the usual length (about five inches) of that part of the drill Ahead which receives the bushing, and the bushing is driven through the drill head from the inside until it protrudes or projects slightly from theouter end, and this protruding or projecting part is then upset or hammered down formingv 'having a a bead 16 which securely holds the bushing in place. lVhen, however, the bushing is to be removed, this protruding or proj-ecting end and the bead 16 may be filed 'or ground oil', or otherwise cut away, and the bushing may then be removed by being driven backward through the head. It vmay be noted that if the spring steel bushing is split longitudinally in driving vit into the head it will be tightly closed, as vwill be understood from the drawing.'

In the drawing the opening in the drill head is shown as being slightly tapered, so that the bushing 15 may be readily driven in and out of the head, but a similar result may be attained by tapering the bushing, as will be understood.

In the use of these stope hammer drills the drill itself is of non-circular form and is slightly turned, at intervals, by the operative who grasps a handle with which the machine is usuall provided, this turning of the drill being a large factor in causing the wear above referred to. In the present ease a usual form of square drill 17 is shown, with chamfered-off corners, and the bushing is of corresponding shape in cross section, but it will be understood that whatever the non-circular form of the drill may be the bushing will be shaped to correspond.

A worn drill head may be provided with a bushing such as is above described at a cost which is only a fractional part of what it would cost to replace the worn drill head by a new one; and a worn drill head which has been hushed, as described, will wear longer, by some two or three weeks, than the original drill head.

Having thus describedmy invention I claim and desire to secure by Letters Patent:

1. A front drill head, for a stope hammer machine, rovided witha split, spring steel bushing tting, tightly 1n said, hea and slightly protruding end which is upset to form a bead to hold the bushing in place, but which bead may be cut away to enable the bushing to be driven out of the head when desired.

2. A front drill head, for a stope hammer machine, provided with an opening therethrough, combined With a` split, spring steel bushing fitting tightly in said opening, and having a slightly protruding endfwhich is upset to form a b ead to holdp the bushing in place,V but which bead may be cut away to enable the bushing to be .driven out ofthe head when desired, the contacting portions of one of said part-s being slightly tapered so that said bushing vmay be driven tightly in said head and may be readily driven out when said bead is removed.

3. A front drill head, for a stope hammer machine, provided with a slightly tapered opening therethrough, combined With a split, spring steel bushing fitting tightly in said opening and having a slightly protruding end which is upset to form a bead to hold the bushing in place, but which bead may be cut away to enable the bushing to be driven out of the head when desired, so

that said bushing may be driven tightly in said head and may be readilydriven out when said bead is removed.

4. A front drill head, for a stope hammer machine, provided With an opening therethrouO'h, combined with a steel bushing fit'- ting tightly in said opening and having a slightly protruding end vihich is upset t0- form a bead to hold the bushing in place, but which bead may be cut away to enable the bushing to be driven out of the head when desired, the contacting portions of one of said 'parts bein slightly tapered so that said bushing may head and may be readily driven out when said bead is removed.

5. A front drill head,vfor a sto e hammer machine, provided witha slight y tapered opening therethrough, combined with a steel bushing fitting tightly in said opening and having a slightly protruding end Which is upset to form a bead to hold the bushing in place, but which bead may be cut away to enable the bushing to be driven out of the head when desired, so that said'bushing may be driven tightly in said head and may be readily driven out when said bead is removed.

In testimony whereof I afx my signature.

ALFRED E. WILLIAMS.

e driven tightly in said 

